1. Field of the Invention
The present invention relates to a flow path structure of a hollow tube for partitioning a hollow portion of a tubular member formed with the hollow portion into a plurality of flow paths by a partitioning member.
2. Description of Related Art
In tubes used in various kinds of machines or apparatus, there is a tube which needs a plurality of partitioned flow paths at inside thereof. For example, in a vehicular engine, lubricating oil needs to supply to rotating portions or sliding portions and lubricating oil is made to flow in a hollow portion formed at inside of a rocker shaft in a hollow shape. Further, in an engine having a variable valve driving mechanism in which opening and closing timings, lift amounts and opening time periods of a suction valve and an exhaust valve are changed at low speed and at high speed of the engine, controlling oil for hydraulically controlling the variable valve driving mechanism is made to flow to a hollow portion of a rocker shaft.
In order to form flow paths for making lubricating oil and controlling oil flow to a hollow portion of a rocker shaft in this way, a technology of partitioning a hollow portion of a rocker shaft into two flow paths by a partitioning wall is described in, for example, Japanese Patent No. 2,741,844 and Japanese Patent No. 2,889,675. According to a technology described in the publications, by inserting an inner tube constituting a semicircular sectional shape into an outer tube constituting a circular sectional shape, at inside of the outer tube, a flow path in the inner tube and a flow path between the outer tube and the inner tube are formed.
Meanwhile, when two flow paths are formed at a hollow portion of a rocker shaft, it is necessary to form an oil supply hole and an oil discharge hole at the outer tube and the inner tube. Therefore, when the two flow paths are formed by inserting the inner tube into the outer tube, the outer tube and the inner tube needs to fix at a predetermined inserting position at which the respective holes of the outer tube and the inner tube coincide with each other. In the case of the related art, the inner tube is pressed-fitted into the outer tube to fix at a predetermined position, or the outer tube and the inner tube are fixed by carrying out drawing operation after insertion. However, since the respective tubes are highly rigid, operation of press-fitting or fixing the position is difficult and when the rocker shaft is long, the operability is poor. Meanwhile, the drawing operation after insertion poses a problem of bringing about a deterioration in the operability or an increase in facility cost and product cost. Further, when the oil supply hole and the oil discharge hole are formed beforehand at the outer tube and the inner tube, operation of fitting the two members may be hampered by producing burr at the inner peripheral face, particularly, it is difficult to remove burr formed at the inner peripheral face of the inner tube and there also is a concern of mixing burr in oil after assembling to hamper operation of the engine.
The invention is for resolving such problems and it is an object thereof to provide a flow path structure of a hollow tube capable of reducing facility cost and product cost by promoting assembling operability.
In order to achieve the above-described object, according to an aspect of the invention, there is provided a flow path structure of a hollow tube comprising a tubular member formed with a hollow portion at inside thereof, and a partitioning member interposed at the hollow portion of the tubular member for partitioning the hollow portion into a plurality of flow paths along an axial direction of the tubular member, wherein the partitioning member comprises a plate member including a partitioning portion for partitioning the hollow portion into the plurality of flow paths along the axial direction, and a close contact portion extended from the partitioning portion and brought into close contact with an inner face of the tubular member for constituting the hollow portion.